Can multiplayer stem pre-owned?

A strong multiplayer offering is all publishers need to discourage consumers from trading in their games.

That's according to Treyarch studio head Mark Lamia, who believes Black Ops' multiplayer is an ideal alternative to the one-time download codes other publishers have introduced in an attempt to dissuade pre-owned sales.

Speaking to MCV at Activision's Call of Duty event in Los Angeles last week, he said: I want to take that in the other direction and bring consumers really great reasons to keep their games, rather than trade them in.

Multiplayer is critical to the success of this series. It has such tremendous staying power – there are millions of people playing Call of Duty every day. It's entertaining people on a magnitude that's mind-blowing and we work really hard to make sure it's supported for a long time.

The effort that goes into the multiplayer is a living thing – we have a team that continues to work on it for World At War. We've done that for a long time and expect to do so for this game.

We're going to support the hell out of Black Ops. That will be our focus post-release: making sure we keep our fans engaged, and hopefully as a result, they'll want to keep playing our game and won't want to trade it in.”

Since the start of the year, publishers such as EA and THQ have used one-time download codes that charge gamers with second-hand copies to unlock the multiplayer mode in titles such as Tiger Woods PGA Tour 11 and UFC Undisputed 2010.

The Treyarch boss was also keen to assure fans that such a tactic will not be used to restrict Black Ops' multiplayer – regardless of whether consumers buy new or second-hand copies of the game.

You won't see that for Black Ops,” said Lamia. The multiplayer comes with the game you buy – you don't have to do anything else for that.”